I'm trying to install CentOS 6.9 on VMware Workstation 15 Pro with custom layout.
One partition ext4 and mount point /boot with 500MB checked to be primary partition, and second partition ext and mount point / with left space of around 20GB also checked to be primary partition. On the reboot after the installation process is finished, booting is stuck on the beginning of the progress bar, I tried to see what is happening in the background.

Also tried on CentOS 6.10 the issue is still present on VirtualBox and VMware Workstation.

We had the same issue with CentOS 7 and we fixed it by changing a datastore from different manufacturer.
I'm interested in the technical details behind this issue, what is the most possible reason for this to happen?